As competition intensifies between service providers of telephony services, providers are looking for services which provide great value and flexibility for their subscribers. Services which increase the likelihood of a calling party reaching the person to whom they wish to contact can provide subscribers with increased flexibility and can increase service provider revenues.
Some service providers today offer flexibility by providing their subscribers with a 1-500 service. The service allows a subscriber to inform a respective service provider which terminals, each of which has a unique directory number (DN), the subscriber wishes to be alerted simultaneously in response to an incoming call to the subscriber's 1-500 number. A directory number is a number which has a direct association with a line appearance on a physical switch and to which a physical terminal is associated. Switch translations are capable of directly translating a DN into a line port or line appearance on a switch within a Wireline or wireless network.
In the event of an incoming call to the special 1-500 number, the service provider's network will correspondingly alert those terminals corresponding to DNs provided by the subscriber and contained in a customer lookup table or profile. The alerted terminal which first responds by going off hook for example is connected to the calling party associated with the incoming call. Incoming calls however, to any of the individual DNs contained in the lookup table or profile rather than the special 1-500 number will however only be routed by the network to the individual terminal corresponding to that DN. Callers who wish to contact a subscriber to the 1-500 service may not be able to if they are unaware of the 1-500 number and the subscriber happens not to be in the physical location corresponding to the individual terminal being called. The 1-500 service is hardly transparent to the subscriber as it requires a separate and additional number.
Other service providers provide their subscribers with substantially the same service by providing a new separate personal telephone number and associate a customer profile to that personal number. The customer profile is used by the service provider's network to assist in the routing of an incoming call to the subscriber's personal number. A caller who is aware of the `personal number` can attempt to reach the subscriber by dialing their personal telephone number and in much the same way as for the 1-500 service an incoming call to the personal number will be routed according to the subscribers profile to one or more of the subscribers terminals, each of which would have their own DN. The shortfalls of this method are substantially the same as for the 1-500 service. Numbers such as the `1-500` and the `personal number` described herein are not considered to be directory numbers as defined in this specification.
As the new generation of Personal Communications System (PCS) networks are deployed over the next few years, a key requirement for the operators of these networks will be offering services that provide the greatest possible flexibility. A major opportunity in this area for example for current wireline and wireless service providers is to provide ways to integrate their respective networks while keeping the integration substantially transparent to subscribers of either network. Of particular interest to service providers in general is to be able to provide a service to their subscribers that would allow them to extend a directory number of one terminal to include other terminals having different directory numbers. To the subscriber the service effectively allows them to create one or more virtual extensions to an existing directory number(DN), where each of the virtual extensions or extended DNs have their own unique network DN. Some of the challenges facing the service providers are how to best implement the service from a cost perspective; how to provide the service such that it is transparent to the subscriber; and how to implement the service such that it is also capable of allowing subscribers to extend a DN associated with one network (wireline or wireless) to include a DN on the other network.